Heat-treating furnace



P 1929- J. SHELTON ET AL 1,728,371

HEAT TREATING FURNACE Filed Jan. 11, 1929 3 Sheets-Sheet 1 INVENTOR5 ATTORNE Y.

P 17, 1929- I. J. SHELTON ET AL 1,728,371

HEAT TREATING FURNACE Filed Jafi. 11, 1929 s SheetsSheet 2 l NV EN TORJ1e JTJs a 70 BY K144919155 Kfima/ A TTORNE Y.

P 17, 1929- J.-SHELTON ET AL 1,728,371

HEAT TREATING FURNACE Filed Jan. 11, 1929 3 Sheets-Sheet 3 3 INVENTORJ 2[e 4 fJ/ zz ran/ 7 BY @flflLEJ l Jim a/ A TTORNEY.

Patented Sept. 17, 1929 I UNITED STATES IRAJ. SHELTON, F DETROIT, AND

PATENT OFFIQE HEAT-TREATING FURNACE Application filed January 11, 1929.Serial No. 331,883.

This invention relates to heat treating furnaces and the object of theinvention is to provide a furnace for heat treating small steel articlesin which the articles are carried through the furnace on a continuousconveyor' from the loading to the unloading position.

Another object of the invention is to provide a heat treating furnace-pfthe charac ter described having movable electrical heating units whichmay be readily removed for repair or replacement if desired.

A further object of the invention is to provide a rotatable drum havinga series of compartments arranged successively about the peripherythereof and adapted to carry the articles to be heat treated, the drumbeing.

slowly rotated to move the compartments from the loading position to theunloading position and through the heating zone.

These objects and the several novel features of the invention arehereinafter more fully described and claimed and the preferred form ofconstruction by which these objects are attained is shown in theaccompanying drawings in which- Fig. 1 is a vertical section through a;heat treating furnace embodying our invention.

Fig. 2 is a perspective view of one of the removable heating elements.

Fig. 3 is an end elevation of the heating furnace partly broken away toshow the construction.

Fig. 4 is an end elevation of an alternative form of furnace.

Fig. 5 is a section through one of the article carrying compartments.

As shown in Figs. 1. and 3 the furnace 7 comprises a stationary housing1 which is preferably lined with refractory material 2 at the sides, topand bottom. This housing 1 carries a pair of bearings 3 at the oppositeends in which a shaft 4 is rotatably mounted. Secured to the shaft 4within the furnace 5 is a drum comprising a hub 5 secured to the shaft 4by the pins 6 and this hub is provided with radiating fins or ribs 7shown in Figs. 1 and 3. Secured to'these ribs is an annular member 8having a .series of refractory facings 9 and a series of rectangularcompartments 10 secured thereto by the rivets 11. These compartments.arefopen ended and are each adapted to receive a container 12 in whichthe articles to be heat treatedare positioned together with the carbonfor carbonizing when the furnace is used as a carbomzmg furnace.

Openings 13 are provided in opposite ends of the furnace in alignmentwith which the container is positioned in the compartment the rotationof-the drum carries the con-"' tainer and compartment through the heating zone between the heating elements 14 provided in each end of thefurnace as shown in Figs. 1 and 3, and within theheating elements 15positioned adjacent the compartments in the exterior of the furnace. Theheating elements 14 are each provided with a pair of terminals 16 towhich a heating element 17 is connected and the ter minals 16 provide ameans for connecting the heating elements in an electric circuit. Theheating elements 15 are longer than the heating elements 14 and are eachprovided with a pair of terminals 18 as shown in Figs. 1 and 2 to whichthe resistance wire 19 is connected, as shown in Fig. 1.

This resistance wire 19 is similar to the resistance wire 17 of theheating element 14 and the terminals 18 provide a means for connectingthe heating elements 15 in an electric circuit. The heating elements 15are each provided with a longitudinal slot or opening 20 through whichthe resistance wire 19 extends and the heating elements 14- and 15 areeach provided with a handle 21 by means of which the elements may beremoved from or replaced in the respective openings in the housing 1.The exterior of each compartment 10 is apertured at 22 so that the heatwill more readily penetrate to the articles being heat treated andannular grooves 23 are provided in the refractory lining 2 which arepacked with soft flexible insulating material 24 such as mineral woolasbestos or like material. The flanges of the member 8 extend into thispacking 23 and reduce the passage of heat toward the interior of thedrum. The drum is also packed with refractory or insulating material 32to reduce the heat passing into the interior of the drum and washers 25are provided on the shaft 4 at each end of the drum to preventoverheating of the shaft 4.

The housing is provided with table brackets 26 adjacent the openings 13throu h which the containers 12 are inserted into t 1e rotatable drumand these containers are carried in the compartments of the drum throughthe heating zone adjacent the heat-- ing elements 14 and 15 and afterthe heat treatment the containers are carried back to the openings 13 bythe continuous slow rotation of the drum at which time a new containermay be inserted into the compartment thus forcing the old container outas shown in Fig. 1.

An alternative form of the -device is shown in Figs. 4 and 5 in whichthe cornpartments are arranged to receive small articles individually.In this case the compartments are arranged as shown in Fig. 5 to provideslots 27 into which small articles such as bolts 28 may be inserted. Forthis purpose a loading table 29, .shown in Fig. 4, is provided at oneside-of the drum adjacent which is an opening (not here shown) to thecompartments. The bolts are inserted into the slots 27 in a horizontalposition and are carried by the drum past the heating.elements 14 and 15to the opopsite side of the furnace and as the bolts pass to a positionbelow the horizontal they fall out of the compartments onto a chute 30which delivers them into a quenching tank 31.

From the foregoing description it becomes evident that the device isvery simple and efiicient in operation, will not easily get out oforder, will automatically heat treat the articles according to the speedof rotation of the drum and provides a device which accomplishes theobjects described.

Having thus fully described ourinvention, its utility and mode ofoperation, what we claim and desire to secure by Letters Patent of theUnited States is 1. In a heat treating furnace, a housing having arefractory lining, a drum rotatably mounted in the housing, to rotate ona horizontal axis, a series of compartments mounted on the periphery ofthedrum, each compartment being adapted to receive a container forarticles to be heat treated, a series of electric heating elementsremovably mounted in the housing about a portion of the periphery of thedrum, .a' seriesof heating elements removably mounted in opposite sidesof the housing adjacent the compartments, the housing being providedwith openings at the bottom through which the containers may be insertedin or removed from the compartments.

2. In a heat treating furnace, a housing having a refractory lining, adrum rotatably mounted in the housing, the drum being ar ranged toreceive articles to be heat treated on the periphery thereof, a seriesof removable heating elements mounted in the housing on opposite sidesof the drum adjacent the periphery of the drum, a series of removableheating elements in the housing about the periphery of the drum, thehousing being provided with loading and unloading plat: forms betweenthe ends of the-heating zone.

3. In a heat treating furnace, a housing having a refractory lining, a.drum rotatably mounted in the housing and havinga series of compartmentson the periphery thereof, a series of heating elements mounted-onopposite sides of the drum in the housing and terminating adjacent thecompartments, a series of heating elements in the housing spaced aboutthe periphery of the drum, the housing being provided with an opening atthe bottom of the drum through which articles may be inserted into orremoved from the compartments.

,4. In aheat treating furnace, a housing having a refractory lining, adrumrotatabl mounted in the housing to rotate on a horizontal axis, aseries of compartments mounted on the periphery of the drum, eachcompartment being adapted to receive a container for articles to be heattreated, the housing being provided with a series of openingstherethrough about the periphery of the drum, and a. series of electricheating elements fitting in the said openings and extending adjacent thecompartments, the heating elements being removable to allow access tothe compartments or replacement of the heating elements.

5. In a heat treating furnace, a housing having a refractory lining, adrum rotatably mounted in the housing, a series of compartments mountedon the periphery of the drum, the housing being provided with a seriesof openings therethrough about the periphery of the drum, and a seriesof electric heating elements fitting in the said openings and extendingadjacent the compartments, the heating elements being adapted forconnection in an electric circuit and being removable to allow access tothe compartments.

In testimony whereof we sign this specification.

IRA J. SHELTON. CHARLES V. JACOBI.

